/*
*
* Copyright 2013 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.netflix.client;

import com.netflix.client.config.IClientConfig;


/**
 * A client that can execute a single request. 
 * 定义执行 request 的客户端 contract（契约）
 *
 * 注意，此接口定义了泛型 S ,T ，仅仅代表了一个是客户端请求（ClientRequest），一个是客户端响应（IResponse）
 * 并没有与具体的通信协议，例如 http，rpc 所绑定。
 * 因此该接口定义的 contract 是广义的请求通信，可以是 http、tcp、udp ftp 或者是本地调用
 * @author awang
 *
 */
public interface IClient<S extends ClientRequest, T extends IResponse> {

	/**
	 * Execute the request and return the response.
	 * It is expected that there is no retry and all exceptions are thrown directly.
	 *
	 * 执行请求和返回响应
     *
	 */
    public T execute(S request, IClientConfig requestConfig) throws Exception; 
}
